Cytology and General Histology: Atlas

Back to top

Connective and supporting tissues

Connective and supporting tissues

  • are remarkable for well-developed intercellular substance with a heterogenous chemical composition and structure that depend on tissue type
  • differ by the number of tissue-forming cell lineages (there can be one or more cell lineages)
  • take part in maintaining homeostasis (steady internal environment) by exerting transport, trophic, protective, biomechanical (supporting), and plastic functions
  • are derived from the mesenchyme

Intercellular substance (extracellular matrix) is produced by cells. It contains fibers and the ground (amorphous) substance

Collagen fibers
  • are formed by fibrous proteins, namely by collagen type I (loose and dense connective tissue, osseous tissue, dentine and cement of teeth) and type II (cartilage tissue)
  • exhibit a higher strength and no potential to be stretched
  • join into bundles, ensure the architecture and mechanical properties of connective tissues
Reticular fibers
  • are formed by collagen type III (reticular tissue, loose connective tissue)
  • are stained by silver salts, so these fibers are called argyrophilic
  • construct 3D-networks and thus exert a sustentacular function
Elastic fibers
  • are formed by such proteins as elastin and fibrillin
  • are selectively stained by orcein and aldehyde-fuchsin
  • branch and form anastomoses, ensure a potential for reversible deformation in connective tissue
Ground (amorphous) substance
  • is constituted by macromolecular complexes of proteoglycans and glycoproteins
  • can be hydrated or mineralized
  • fills spaces between cells and fibers, participates in exerting the transport, trophic, and sustentacular function
  • is formed during the embryogenesis by cell migration from the mesoderm (endomesenchyme) and neuroectoderm (ectomesenchyme)
  • is a group of various cells (different in their determination) and jelly-like intercellular substance
  • undergoes cell differentiation that depends on the surrounding cells